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Design and analysis of multiple input autopilots using sliding modes in order to achieve accurate horizontal and vertical plane control of an autonomous underwater vehicle over a wide variation of speeds is presented. The simulated vehicle is equipped with two (fore and aft) sets of dive planes and two sets of rudders. In addition, two vertical and two horizontal thrusters are provided for control during low speed or hovering operations. The entire range of vehicle speeds from zero speed...
Topics: Mechanical engineering, Marine engineering., Autonomous Underwater Vehicles, AUV, Guidance Control
Naval Postgraduate School
by Seveney, James Arthur; Steinberg, Guenter Peter
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The U.S. Navy has recently embarked on a program called Next Generation Computer Resources (NGCR) whose aim is a cooperative effort between Navy and industry to field a set of state of the art computers for shipboard use in the late 1990's. One of the important features of NGCR is the use of commercial hardware developed to standardized protocol and ruggedized for military applications. This protocol provides for compatibility between machines. The machines themselves may be of any architecture...
Topics: Requirements engineering, Software engineering., Combat Direction Systems, Software Engineering,...
Naval Postgraduate School
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This thesis examines the feasibility of using an expert system approach to design an intelligent Weapon Suggestion System (WSS) to assist the Weapons Department Head (WDH) on board a naval warship in making accurate and efficient decisions in critical battle situations. We have analyzed the constraints of a WSS and the performance of on board weapons. We have also reviewed the related material previously published and discussed the implementation environment in this thesis. The system is...
Topics: Weapons systems, Evaluation, Systems engineering.
Naval Postgraduate School
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This thesis sought to perform developmental flight testing of a half- scale unmanned air vehicle. To do this the half scale version of the Pioneer (used by the US Marine Corps for training) was chosen as the airframe to instrument because of problems that the Unmanned Air Vehicle Office at the Pacific Missile Test Center had identified in the full scale version of the Pioneer. Problems included: (1) discrepancies in the predicted and flight tested rate-of-climb, time-to-climb and fuel flow at...
Topics: Aerospace engineering, Vehicles, Remotely piloted, Aerodynamics.
Naval Postgraduate School
by McIntyre, Eddie L.
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An evaluation of the shielded stripline was conducted using an X-band waveguide to isolate a suspended strip transmission line. The analysis was conducted below the functional cutoff frequency of the X-band guide over a broad range of frequencies. The scattering coefficients were measured and used to compute the gap capacitances of the transmission line. The gap discontinuities were then used to confirm the theoretical assumed piequivalent circuit.
Topics: Strip transmission lines, Systems engineering, Electronics in military engineering., Suspended...
Several heuristics and algorithms have been developed to find minimal sum-of-products expressions in binary logic. Most of them use prime implicants during minimization process. An efficient search strategy has been developed for finding minimal sum-of-products expressions for multiple-valued logic (MVL) functions by using the constrained implicants set concept. The search space can be considerably reduced over the only other known exact minimization technique and exhaustive search. The primary...
Topics: Electrical engineering, Computer engineering, Computer input-output equipment, Constrained...
Naval Postgraduate School
by Sanchez M., Juan Jose
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The error introduced by the DF accuracy of three direction Finding equipments used on board two surface units providing bearing measurements is used to evaluate the performance of the ESM systems through the Extended Kalman Filter equations, and to appreciate the result in the estimation process by evaluating how the improvement of the tracking process is reduced as the error introduced by the DF accuracy of the ESM systems is increased. The process is conducted at three different scenarios...
Topics: Systems engineering, Electronics in military engineering., Kalman Filter, Direction Finding, ESM...
Naval Postgraduate School
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This thesis describes a CAD-compatible circuit model for an infinitesimally thin inductive strip centered in homogeneous finline for 0.1 less than or equal to w over b less than or equal to 1.0. The model is shown to predict scattering data which agrees with data computed using the spectral domain method. Results were generated for strips of length T greater than or equal to 10 mils in X-band. By applying the scaling principle, the model is valid for any waveguide band over the normal frequency...
Topics: Electrical engineering., Finline, Discontinuity, Inductive, Strip
Naval Postgraduate School
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Multi-Frequency Modulation (MFM) has been developed at NPS using both differential quadrature-amplitude-modulation (DQAM) and differential quadrature- phase-shift-keying (DQPSK) encoding formats. This report discusses the use of each of these formats in transmitting a facsimile encoded message over a voice frequency channel. The satisfactory transmission and receipt of facsimile messages was achieved using both DQPSK and D16-QAM encoding formats. Research and testing for this report included...
Topics: Engineering, Signal processing., Facsimile, MFM, Communications
This thesis describes a CAD compatible circuit model for an inductive strip with finite metal thickness centered in finline with wb=1. Scattering coefficients predicted by the circuit model are in good agreement with those predicted by an electromagnetic model based on Maxwell's equations. Filter simulations using the circuit model predict responses which are in good agreement with laboratory measurements.
Topics: Electrical engineering, Electronics, Computer-aided design.
Naval Postgraduate School
by Narveson, Marshall L.
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The Naval Postgraduate School (NPS) has undertaken a series of studies on ship air wake tailoring, through the use of deflectors, with the goal of reducing the level of turbulence and the size of the separated zones on the helicopter deck. This reduction will result in a larger engagedisengage envelope, which in turn, will increase the percentage of time that the H-46 and other helicopters can safely operate. This study is the second in the series of NPS to attempt to achieve this goal and...
Topics: Engineering, Aerodynamics, Marine engineering., Backward Facing Step, Flow Visualization, Bluff...
Naval Postgraduate School
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Fault trees and Petri nets are two widely accepted graphical tools used in the safety analysis of software. Because some software is life and property critical, thorough analysis techniques are essential. Independently Petri nets and fault trees serve limited evaluation purposes. This thesis presents a technique that converts and links Petri nets to fault trees and fault trees to Petri nets. It enjoys the combinational benefits of both analysis tools. Software Fault Tree Analysis and timed...
Topics: Computer science, Software engineering, Graphic methods., Software Safety, Petri Net, Fault Tree,...
Naval Postgraduate School
by Sudjiwo
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The open-end resonator in suspended substrate transmission line was analyzed in terms of two open-end discontinuities on a line segment. A procedure for computing the resonant frequency and constant of propagation was demonstrated using a full wave analysis. The fringing capacitance was computed using an equivalent length extension model and a transmission line circuit model. The characteristic equation was derived using Galerkin's method applied in the Fourier transform domain. The calculation...
Topics: Systems engineering, Electrical engineering., Spectral Domain Approach, Suspended Substrate Line,...
Naval Postgraduate School
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The necessity for well-defined, integrated information systems (IS), driven by today's dwindling human, financial, and management resources, makes it essential to plan effectively. This can only be achieved by linking IS planning to the overall strategic plan of the organization. Department of the Navy (DON) IS planning has historically missed the mark in this report. Information Engineering, automated through Computer Aided Software Engineering (CASE) technology, offers significant benefits...
Topics: Management, Engineering, Computer programs, Computer-aided design., Strategic Information System...
The effects of the state excitation matrix Q underlined sub k in the smoothing routine of an extended Kalman filter is investigated. A new algorithm to derive the Q underlined sub k matrix is also developed. In addition, the accuracy of the filter was substantially improved by implementing a new maneuver detection technique. Several tracking scenarios are simulated and analyzed for noise free and noisy cases and statistical data are obtained for the maneuver detection technique. The program...
Topics: Engineering, Science, Noise, Kalman filter, smoothing, noise process, maneuver detection
Naval Postgraduate School
by Kurtoglu, Levent
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This thesis introduces the effect of the loss to the homogeneous finline strip model. The expressions for the Quality Factors associated with the ohmic losses for inductive strips in homogeneous finline are derived and included in the CAD compatible circuit model in terms of the finite Q inductances. It is shown that the lossy circuit models more accurately predict the experimental response of an X band finline filter.
Topics: Engineering, Signal processing., Finline, Inductive Strip, Finline Discontinuity, Ohmic Losses
The U.S. Navy is constantly looking toward using more lightweight and compact heat exchangers. One of the areas of interest is the use of enhanced boiler tubes in the evaporator of a refrigerator plant, thereby cutting down on the number of tubes needed. The present research is a continuation of work done at NPS concentrating on the boiling characteristics from small tube bundles sitting in a pool of pure R-114, simulating the evaporator in such a heat exchanger. Two types of commercially...
Topics: Mechanical engineering, Heat, Transmission, Thermodynamics., Heat Transfer, Pool Boiling
Naval Postgraduate School
by Barnes, Christopher A.
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This thesis presents a simple and efficient method of implementing a semantic type checking system for use with relational databases. Numeric data typically represent measures of a specific property or characteristic of a real world object. Computers manipulate only the numeric value. It is the responsibility of the user to ensure that the data are handled in a manner consistent with its meaning. If the semantics associated with the numbers are stored in a data dictionary, semantic consistency...
Topics: Systems engineering, Semantics, Databases, Database design, data manipulation, semantic networks
Naval Postgraduate School
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Numerous methods exist to calculate near-fields from two-dimensional objects, however, relatively long computation times are generally required for reasonable accuracy. Computation is slowed primarily due to the calculation of near-fields using a singular kernel. The proposed work will develop an alternate, more efficient algorithm for calculating the near-fields from surface distributions. The Singularity Extraction Technique (SET) analytically extracts the contribution due to the...
Topics: Electrical engineering, Near-fields., Electromagnetic scattering, near-fields
Naval Postgraduate School
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A classical control system with a full-order observer is designed to stabilize the motions of towed vessels. The control method is transverse movement of the towline attachment point on the towed vessel. The linearized sway and yaw equations of motion are developed, leading to the control system design. The control system is tested using MATRIX. Results for a barge, mariner-class ship and a tanker are presented. Possible benefits of the implementation of such a system include improved fuel...
Topics: Marine engineering, Tankers, Warships., Towing, control, stability, automatic control system
Naval Postgraduate School
by Zagourakis, Emmanouil N.
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The purpose of this study is to determine whether or not a program could be developed to examine isomorphism between parts of a VLSI layout. Many simulation files, obtained through Magic's hierarchical extractor, were analyzed in order to develop a C program to accomplish recognition in several types of gates. This recognition gives signatures in order to check for isomorphism. The development and design of the algorithms used in different parts of the program are described. Results demonstrate...
Topics: Algorithms, Electrical engineering., VLSI circuit verification, gate recognition, isomorphism...
Prediction of ionospheric propagation in polar regions tends to be difficult because of an increased number and variety of local ionospheric disturbances. Various programs have been developed to model ionospheric propagation, and one such program, IONCAP-PC 2.5, is tested for accuracy over a transpolar communications link, using noncentric measured reference data obtained from the Univercity of Leicester. The field strength values predicted by IONCAP-PC 2.5 are extended to take into...
Topics: Electrical engineering, Ionosphere., High Frequency (HF), Ionospheric Propagation
Naval Postgraduate School
by Huber, Ronald Scott
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This thesis describes the design methodology and the process of employing the GENESIL Silicon Compiler (GSC)(Version 7.1) in the layout of a pipelined multiplier, in 1.5 micron CMOS technology, using a parallel multiplier cell array. Additionally, background material on the theory of multiplication, as well as the concept and theory of pipelining are presented. The results revealed two practical limits of the GSC system which precluded achieving the high component density made possible by full...
Topics: Engineering, Computer-aided design, Multiplication., Silicon Compiler, Pipeline, Digital Multiplier
The mechanical properties of any material with a discontinuous second phase dispersed in a matrix are recognized to be influenced by the distribution of the second-phase particles. Current models for the prediction of material properties from particle distributions are based on the assumption of a random particle distribution. Through computer simulation, nearest-neighbor particle spacings have been calculated for random and non-random distributions. For low fractions, random distributions...
Topics: Computer simulation, Engineering, Science., Particle distribution, computer simulation
Electronic support measures (ESM) systems play an increasingly important role in modern warfare and can influence the outcome of a military engagement. The application of ESM can be extended to anti-guerrilla and anti-drug operations where law enforcement agencies can exploit the fact that their presence is inducing the outlaw to depend more on radio communications to coordinate their activities. When a propagation path of no more than one reflection at the ionosphere (1-hop) can be assumed,...
Topics: Electrical engineering, Electronics in military engineering, Modeling., Single-Sight-Location,...
Naval Postgraduate School
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This thesis examines the system implementation considerations of a resonance based radar target classification system. The basis of the system is the aspect and excitation independent property of electromagnetic scattering from a conducting body. Such a system consists of two components: pole extraction and annihilation filtering. The algorithms investigated here for these purposes are the Cadzow-Solomon pole extraction algorithm and the K-Pulse annihilation filter. Additionally, an...
Topics: Systems engineering, Electronics in military engineering., Natural Resonances, Noncooperative...
Naval Postgraduate School
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Ship silencing is an important issue of modern naval warfare. For a long time, naval ship engineers have tried to reduce the noise from the vibration of shipboard components. Ths is important for a ship to accomplish its mission with good survivability. One method, called constrained viscoelastic layer method, uses shear deformation in viscoelastic material to absorb and dissipate the vibrational energy of the system. It shows promise in damping over a broad frequency spectrum of vibration. A...
Topics: Mechanical engineering, Sound., Vibration, damping, viscoelastic material, constrained layer damping
Naval Postgraduate School
by Powell, Joyce L.
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This thesis attempts to document the events environment, decisions, and personnel involved in the development, implementation and life cycle management of a computer software application. The computer application is developed using a prototyping methodology and a third generation software language for a Department of the Navy Headquarters Command. The data are presented in a case study format and are analyzed in accordance with software life cycle development principles and change management...
Topics: Computer programming,Software, Software engineering., Prototype development, case studies
Naval Postgraduate School
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The use of Computer-Aided Software Engineering (CASE) tools has been viewed as a remedy for the software development crisis by achieving improved productivity and system quality via the automation of all or part of the software engineering process. The proliferation and tremendous variety of tools available have stretched the understanding of experienced practitioners and has had a profound impact on the software engineering process itself. To understand what a tool does and compare it to...
Topics: Computer programming, Software, Software engineering, Computer-aided software engineering, Rapid...
Naval Postgraduate School
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The purpose of this thesis was to revitalize the Naval Postgraduate School's 3.5' x 5.0' academic wind tunnel. The wind tunnel had sustained previous damage to one of two sets of counter-rotating blades. Because of this change in configuration, a wind tunnel calibration was deemed necessary. Along with the calibration a digital data acquisition system was designed and implemented to aid in the data collection, storage and analysis for this project and future projects, using this wind tunnel....
Topics: Engineering, Aeronautics, Calibration., Wind Tunnel Calibration, Wind Tunnel Turbulence
This research considers communication amongst a community of earth terminals through a collection of low altitude earth oriented satellites (LASAT) . In one proposed LASAT system, all satellites are identical and simultaneous transmission of near identical signals from several satellites creates interference at the earth receivers. Frequency hop sequence (FHS) is a new form of frequency hopping (FH) and is the proposed spread spectrum LASAT communications technique considered in this research....
Topics: Telecommunication systems, Noise, Electrical engineering., Frequency hopping, satellite...
Electromagnetic scattering from rough surfaces is of prime importance in the engineering field since it affects communications, radar, remote sensing, acoustics, etc. The actual problem of scattering from rough surfaces is complicated and involves three dimensional scattering from either lossy or dielectric, electrically large surface. Integral equations are widely utilized to solve this kind of problem but this solution to the problem is generally computationally intensive. In the On-Surface...
Topics: Electrical engineering, Radiation, Linear systems, Optics., Electromagnetic scattering, Period...
Naval Postgraduate School
by Fountain, Harrison Douglas
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The DoD requirements for software are growing almost as rapidly as the escalating cost of developing the software. The new rapid prototyping paradigm is an innovative approach to software development, which modifies the traditional life cycle model. This thesis features a comprehensive survey and evaluation of the rapid prototyping paradigm. The survey describes the rapid prototyping process, the complex prototyping support system environment required, proposed rapid prototyping methodologies,...
Topics: Computer programming, Computer software., DoD software goals, Prototypes, Engineering, Rapid...
Naval Postgraduate School
by Wilhelm, Joseph Arthur, Jr.
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The Naval Post Graduate School has obtained software which can be used for the thermal analysis of an electronic component. This software includes two versions, one for steady state analysis and the other for transient analysis. Each version consists of two programs, a model builder and a thermal analyzer. This thesis describes a user friendly, menu driven specific model builder which may be used to rapidly generate a thermal model, containing up to 750 nodes, for a microcircuit die. This model...
Topics: Electrical engineering, Thermal analysis, Computer programs, Thermal Analysis, Computer Aided,...
Naval Postgraduate School
by Vourazelis, Dimitrios G.
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This thesis is a design of an alternative system which may provide heating to the Naval Postgraduate School swimming pool. Particularly, it is a solar heating/photovoltaic system designed for a better efficiency and less cost of installation and maintenance. Principles of heat transfer, control and fluid dynamics theory are used for the determination of this heating system elements. The feasibility of its installation and use is analyzed.
Topics: Photovoltaic power generation, Solar energy, Electrical engineering., Optimization, Solar Heating,...
Naval Postgraduate School
by McKenzie, Robert Hugh, III
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A proof-of-concept experimental validation of a proposed idea for encoding spatial images using masks with patterns based on a set of orthogonal Walsh functions was conducted. Simple images were encoded via a multiplexing technique, and computer algorithms were developed to decode and to display the results. Photographs of the re-constructed images offer incontestable proof of the validity of this hypothesis for multiplexed imaging. Further research of this technology is expected to lead to...
Topics: Multiplexing, Spectrum analysis, Walsh functions, Sequency theory, Engineering, Spectroscopy, Walsh...
Naval Postgraduate School
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The purpose of this thesis is to design and implement a concrete interface generation system. The concrete interface generator is a software system which takes a formal specification as input and generates the specification part of an Ada implementation as output. Attribute grammars and fourth-generation language tools have been used in the implementation of this system. Spec, a formal language for writing black-box specifications for large software systems, was used as the input for the...
Topics: Computer programs, Software engineering, Specifications., Automatic code generation, formal...
Naval Postgraduate School
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Today, in addition to standard data like numerics and alphanumerics, it is possible to capture, sort, manage, retrieve and present different media information, e.g. sound, image, graphics, text and signals, by using the current, modern computer technology. The Multimedia Database Management System (MDBMS) project, which started at the Computer Science Department of the Naval Postgraduate School in 1988, studies not only the storing, managing and retrieving different media information, but also...
Topics: Databases, Systems engineering., Multimedia Database Management System, Multimedia, DBMS, MDBMS,...
The objective of this work is to outline rules for the implementation of Electronic Warfare Reprogramming Libraries (EWRL) in the Brazilian Air Force (FAB). First, a brief description of the structure and functions of the relevant branches of Brazilian Air Force will be presented. Second, why having a reprogramming process for airborne RADAR WARNING RECEIVERS (RWR) THREAT LIBRARIES is important at the current stage of EW development within the Brazilian Air Force. Third, based on the U.S....
Topics: Electronics in military engineering, Computer programming, Threats., Radar warming receivers, user...
Naval Postgraduate School
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This thesis deals with the procedures for and the issues in the analysis, design, and implementation of Library Loan Management System (LLMS). LLMS is a low-volume real-time transaction processing system intended for small or medium size libraries. It is designed to provide such library functions as library cataloging, patron registration, circulation, and reference services based on a relational database management system. We implemented prototype LLMS to run on IBM PC/AT or XT compatible...
Topics: Computer systems, Information science, Systems engineering., Database system design and...
Naval Postgraduate School
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The Kalman filter is used to provide estimates of the position and velocity of a storm based upon observation of the storm's longitude and latitude. Nonstationary noise is shown to degrade the performance of the filter and cause tracking divergence. Time varying values for the noise covariance matricies R and Q, and the addition of an external forcing function to the filter, effectively compensated for this tracking error. Results for the simulations show significant performance advantages of...
Topics: Electrical engineering, Cyclones, Latitude, Longitude, Storms, Weather forecasting, Tropics.,...
Naval Postgraduate School
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The sliding model control is known as a robust control that is able to work under the uncertainties of modeling error and the environmental disturbances. The objective of this research is to design the simple control (sliding control) algorithms for a single-link flexible arm and to study the robustness due to varying payload. A general form of physical plant in state space is formulated. To achieve a continuous control, a time-varying boundary layer was introduced into the control system...
Topics: Mechanical engineering, Computer systems, Mechanics, Sliding Mode Control, Flexible Arm, Control of...
The allocation of effort to quality assurance and testing is vitally important to the successful development and maintenance of a software system. There is no quantitative method for finding the right allocation policy. The most common methods include allocating fixed percentage of effort for all software projects or using allocations that have been used for similar projects in the past. The benefits of choosing the correct manpower allocation to suit a particular project can be substantial....
Topics: Artificial intelligence, Cybernetics, Software engineering., expert systems, project management,...
The Pseudo Wigner Ville Distribution is a time frequency representation of an input time signal and is ideally suited for portraying non-stationary signals. A working computer program is presented and the effect of preprocessing and postprocessing data manipulations is shown. The program has been developed for analyzing data for use in machinery condition monitoring diagnostics and will be valuable asset for analyzing transient machinery. A practical example showing pump speed variations with...
Topics: Mechanical engineering, Time-signals, Machinery, Monitoring., Machinery monitoring, transient,...
This thesis suggests a method to estimate the current value of an ionospheric parameter. The proposed method is based on the known variability of the observed current values near path and utilizes data derived from ionospheric sampling measurements. Analysis of errors is provided in Single-Site-Location High-Frequency Direction Finding (SSL-HFDF), arising from ionospheric irregularities such as Es (sporadic E), ionospheric tilts, and traveling ionospheric disturbances (TIDs). The...
Topics: Ionosphere, Systems engineering, Radio, Single-Site-Location, Direction-Finding, High-Frequency,...
Increase in the demand for software, coupled with concerns regarding cost overruns and schedule delays in software development lead experts to believe that the United States will be unable to produce the software it needs. In order to improve their performance, software professionals must first understand the development process. The System Dynamics model of software project management provided a tool for the understanding of a single project. This tool was expanded to model a multiproject...
Topics: Computer programming, Computer software, Software engineering., Multiproject management, human...
ARGOS is a multimedia database prototype system currently being developed by the Computer Science department of the Naval Postgraduate School in Monterey. Its primary purpose is to provide a prototype system that could be used as a Battle Group Commander's assessment tool and a shipboard data management tool. In addition to providing increased efficiency and productivity to the Navy ships. This implementation demonstrates the contribution such a system would make to the efforts of the...
Topics: Computer programs, Database management, Databases., Software engineering, acoustic database, event...
Naval Postgraduate School
by O'Leary, Paul J., Jr.
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The purpose of this thesis is twofold: first is to describe the current Marine Corps fire support system as an overall architecture and the second is to provide teaching materials for the Joint C3, (Command, Control, Coordination) curriculum. The emphasis will be to identify and illustrate the various command, control, and coordination procedures that are evident throughout the system. The system architecture described will provide a foundation from which the student will be required to design...
Topics: Command and control systems, Systems engineering., Fire support, Command, Control, Coordination...
Naval Postgraduate School
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The results of an aircraft parameters identification study conducted on the National Aeronautics and Space AdministrationAmes Research Center Advanced Concepts Flight Simulator (ACFS) in conjunction with the Navy-NASA joint Institute of Aeronautics are given. The ACFS is a commercial airline simulator with a design based on future technology. The simulator is used as a laboratory for human factors research and engineering as applied to the commercial airline industry. Parametric areas examined...
Topics: Aeronautics, Engineering, Parameter Identification, Aircraft Simulator, Advanced Concepts Flight...
Progress in computers during the past two decades has sparked the development of many useful high frequency (HF) ionospheric propagation prediction codes. The high-latitude (polar) ionosphere still remains as the most difficult propagation region to predict. A 'Non centric database of collected high-latitude signal and noise measurements was obtained during 1988 and 1989 by the University of Leicester, UK The Advanced Prophet 4.0 HF Ionospheric Propagation Prediction Code was exercised and...
Topics: Electrical engineering, Computer programming, Radio frequency, Communication., High Frequency (HF),...
Naval Postgraduate School
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Two recent computer programs, WRCOMP and ENGINE, by A. Mathur, were used to examine the performance to be gained by incorporating a wave rotor component in a turbofan engine with mixed exhausts. The programs were transferred to a VAX-2000 computer, extended, and test cases reported by A. Mathur were successfully reproduced. A comparison was made between ENGINE, in which real gas effects are accounted for, and ONX (by J. Mattingly) in which constant specific heats are used. The inclusion of real...
Topics: Aerospace engineering, Waves, Rotors., Turbofan Engines, Turbofan engines with a Wave Rotor
Naval Postgraduate School
by Nedresky, Donald L.
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An adaptive control system is a system that detects changes in the plant parameters and makes necessary adjustments to the systems performance. This thesis examines the use of parallel distributed processing systems (neural networks) in adaptive control. A general neural network structure is introduced and a description of the Backpropagation paradigm is given. A discussion of adaptive control theory including the one step ahead prediction control algorithm and the linear least squares...
Topics: Engineering, Aeronautics, Flight control., Neural Networks, Adaptive Control, Backpropagation,...
Naval Postgraduate School
by Thornlow, Robert Timothy
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Several techniques for estimation of the power spectral density (PSD) , or simply the spectrum, of discretely sampled short data sequences are investigated in this thesis. These techniques are directly based on the fast Fourier transform (FFT) of the data sequence. However, an extrapolated version of the original data sequence will be used instead of the original. The aim is to enhance the resolution of the true spectral components of the signal without adding any false frequency components....
Topics: Electrical engineering, Electronic data processing., Data Extrapolation, Periodogram, AR spectral...
A low-speed wind tunnel investigation was conducted to examine the vortex wake downstream of a three-percent scale model of the YF-17 lightweight fighter prototype at high angles of attack. The study was in support of NASA ames Research Center's wind tunnel investigation of a full scale FA-18 as part of NASA's High Alpha Technology Program. Smoke flow visualization was used to locate the downstream vortex wake. Hot-wire surveys were taken through the vortex at two stations; one directly aft of...
Topics: Engineering, Aerodynamics., High Angle-of-Attack Aerodynamics, Hot-Wire Measurements, Wind Tunnel...
Naval Postgraduate School
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Current conventional Database Management Systems (DBMS) manage only alphanumeric data. However, data to be stored in the future is expected to include some multimedia form, such as images, graphics, sounds or signals. The structure and the semantics of the media data and the operations on that data are complex. It is not clear what requirements are needed in a DBMS to manage this kind of data. It is also not clear what is needed in the data model to support this kind of data; nor what the user...
Topics: Computer science, Management information systems, Systems engineering., Multimedia Database...
This thesis represents an initial attempt to demonstrate aspect independent target identification of complex radar targets using annihilation filters based on the natural resonances of the targets. The Cadzow-Solomon signal processing algorithm is tested to determine its suitability for the task of extracting the poles from complex targets to a degree of accuracy required for successful implementation of an annihilation filtering target identification system. This testing was conducted through...
Topics: Electrical engineering, Radar, Signal processing., Pole Extraction, Cadzow-Solomon, Annihilation...
Software project development has been plagued with an infamous reputation for cost overruns, late deliveries, poor reliability and users' dissatisfaction. Much of this blame has been placed on the managerial side of software development. The Systems Dynamic Model of Software Project Management is a quantitative model of software project dynamics that is attempting to gain some valuable insight into the managerial side of developing software systems. The objective of this thesis is to use the...
Topics: Computer programming, Software, Software engineering, Heuristics, biases, software project...
Naval Postgraduate School
by Ives, Robert W.
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Multi-frequency modulation (MFM) has been developed at NPS using both quadrature-phase-shift-keyed (QPSK) and quadrature-amplitude-modulated (QAM) signals with good bit error performance at reasonable signal-to-noise ratios. Improved performance can be achieved by the introduction of error control coding. This report documents a Fortran simulation of the implementation of error control coding into an MFM communication link with additive white Gaussian noise. Four Reed-Solomon codes were...
Topics: Electrical engineering, Cybernetics, Telecommunication systems., Multifrequency Modulation,...
With the fast pace of technology in the aerospace industry, there are increasing demands for higher strength and stiffness in structural materials but with reduced weight and improved formability. Aluminum alloys have been widely used in the construction of aerospace vehicles because of their high strength to weight ratio, forming characteristics and corrosion resistance. An investigation was conducted to determine the temperature and composition dependence on the activation energy for creep of...
Topics: Mechanical engineering, Lithium, Temperature., Temperature, composition, activation energy, creep...
The development and structure of Dean vortices in a high aspect ratio curved channel were measured and studied for Dean numbers from 35 to fully turbulent conditions. Mean vorticity components were determined from measurements of the three components of mean velocity, which were measured using a miniature five-hole pressure probe. Streamwise, radial and spanwise vorticity components measured 120 deg from the start of curvature, show evidence of Dean vortices in the time-averaged flow field....
Topics: Mechanical engineering, Fluid mechanics, Speed, Dean Vortices, Dean Number, Rectangular Curved...
Naval Postgraduate School
by Mattes, Victor R.
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Light microscopy, scanning electron microscopy, and transmission electron microscopy were employed to examine the microstructural basis for the mechanical properties of as-quenched and tempered HSLA-100 steel. Examination of the alloy revealed granular bainite with martensite and retained austenite in the as-quenched state which upon aging at temperatures below the lower transformation temperature, 677 C, formed tempered bainite with precipitates of copper and carbides. These results indicate...
Topics: Steel, Microstructure, Copper, Tempering, Precipitation hardening, Mechanical engineering.,...
Naval Postgraduate School
by Noble, Michael Lynn
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This thesis presents a preliminary design of the electrical power system (EPS) for the Naval Postgraduate School's Petite Amateur Navy Satellite (PANSAT). The EPS is a photovoltaic silicon cell system consisting of solar array, batteries, battery charge regulator (BCR), and dc-dc convertors. The EPS provides power for up to two years of low earth orbit (480 km) operations. The solar array consists of 17 panels with thirty-two 2x4 cm solar cells in series on each panel. The cells have an...
Topics: Electrical engineering, System design., PANSAT satellite, electrical power system, battery charge...
Naval Postgraduate School
by Guilmette, Daniel J.; Wilson, Georgette P.
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In this theses, we propose a relational database design based on the information which the United States Military Academy is required to maintain, the frequency of use of this information, as well as current and future applications. Included in this design are the Enhanced Entity Relationship Diagram (reflecting the entities and their relationships to one another), the attributes for each entity and relationship (located in the tables), and the functional dependencies from which the diagram and...
Topics: Databases, Systems engineering, Computer files., EER Diagram, Relational Database Design,...
This research demonstrates the Galerkin FEM's ability to provide approximate solutions of second order, nonlinear, one dimensional, two point boundary value problems. The research concentrates on the development of linearization, iteration, and interpolation strategies for the solution of differential equations containing the nonlinear u2 term. Additionally, various numerical considerations are explored. Over 2000 cases were analyzed using various strategies and results detailing the efficacy...
Topics: Mechanical engineering, Finite element method, Computer programs., Galerkin FEM, nonlinear,...
Naval Postgraduate School
by Kaoutskis, Michael T.
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Several data compression schemes have been investigated for reducing storage space and transfer time via a computer network. The primary goal of this thesis is to develop a new scheme for data compression ratio better than the already existing schemes. The main approach adopted by this research is a combination of dictionary look up and entropy source coding.
Topics: Electrical engineering, Algorithms, Encyclopedias and dictionaries, Computer networks., Entropy...
The need for data management standardization has been clearly identified by the Office of the Secretary of Defense as a means to realize savings in the 9 billion dollars spent annually on information technology in DOD and to further the sharing of information. This thesis discusses the importance of data requirements, functional requirements, logical database design and application design for a prototype microcomputer dictionary system for standardizing, storing, updating and viewing data...
Topics: Computer programs, Standardization, Systems engineering., Data management standardization, data...
Naval Postgraduate School
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A computer simulation model of the U.S. Marine Corps Marine Expeditionary Force's high frequency and very high frequency voice radio system was developed. The model's performance, under varying message traffic loads and jamming, was evaluated and compared to two computer models that incorporate telephone switching techniques to access multiple radio circuits. A radio circuit switch mathematical model was developed utilizing an Engset distribution for a telephone exchange to calculate the key...
Topics: Engineering, Communication, Signal processing., VHF radio, HF radio, Single channel radio, Circuit...
Naval Postgraduate School
by Anderson, Steven E.
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As fiscal impacts continue to make the U.S. Navy's budget increasingly austere, diligent efforts are being made to enhance the Navy's warfighting capability and streamline its operations. In this environment, it is necessary to efficiently produce computer systems that meet fleet requirements and do so at minimal cost. This thesis illustrates a methodology that integrates rapid prototyping with formal requirements analysis of a Generic C3I workstation. Traditional requirements analysis and...
Topics: Software engineering, Cost, Software specification, hard real time software, embedded systems,...
Testability issues concerning the need for including Design for Testability (DFT) techniques in VLSI (Very Large Scale Integration) designs are discussed. Types of fault models, the use of fault simulation and the DFT techniques of Scan Path and Built in Test are described. An engineering methodology that uses the Genesil Silicon Compiler to produce a VLSI design, DFT-CHIP, which utilizes the DFT Scan Path technique is presented. Included are the procedures for using Genesil's simulation,...
Topics: Electrical engineering, Computer-aided design., Design for testability, VLSI, Genesil Silicon...
Naval Postgraduate School
by Smith, Wallace Dean, Jr.
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The E-2C Hawkeye, a U.S. Navy aircraft, has experienced problems with fatigue cracks in its wings. This problem was studied in the laboratory using a representative specimen under simulated flight loading. Acoustic emission monitoring was used to detect the stress pulses emitted during cracking. A new wave analysis technique was applied in order to distinguish extraneous noise from crack growth. This technique distinguishes between the extensional and flexural waves in thin aluminum plates....
Topics: Engineering, Science, Aluminum, Fatigue., aircraft fatigue, aging aircraft, crack growth, 7075...
Naval Postgraduate School
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The capability of an electromagnetic radiating system depends on its ability to operate effectively in a complex environment, where its pattern performance can be limited by pattern distortion effects. On a modern military ship, this task is complicated by the large number of systems that are competing for prime locations. It is recommended, therefore, that a given situation be studied systematically, looking at individual pieces of the problem separately and developing intermediate...
Topics: Electrical engineering, Modeling, Radio frequency, Radio wave propagation., Inverted Cone Antenna,...
Naval Postgraduate School
by Kim, Hyung Suk
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This thesis describes the tactical EO/IR system requirements and characteristics for the Republic of Korean Army. Many key ideas of these are centered on rough terrain condition, severe weather condition and tactical usage of EO/IR system in Korean peninsular. And finally, the future trends of ground tactical EO/IR system and some recommendations for Korean Army are presented.
Topics: Electrooptical devices, Infrared detectors, Tactics, Electronics in military engineering.,...
Naval Postgraduate School
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This thesis presents a study of the atmospheric refractivity conditions in the oceanic area arund Central America and a description of the possible propagation effects on surveillance systems. The basic principles of atmospheric refraction are presented along with the techniques used to determine the occurrence of atmospheric ducts and to characterize the type of refractive profiles occurring at a station. Radiosonde data collected by coastal stations in the area were used to establish...
Topics: Electronics in military engineering, Central America, Radar in aeronautics, Radar, Refraction,...
The engineering qualification model of the FLTSATCOM satellite was donated and is to be used for instructional laboratories and research. With the acquisition of this spacecraft, a course was established on spacecraft testing with the intent of using the qualification model as a lab device. The course requirement calls for the ability to power up, power down, and configure the satellite within a reasonable time frame. The objective of this thesis is to produce a single source implementation...
Topics: Engineering, Astronautics, Communication systems, Satellites., Fleet Satellite Communications,...
Naval Postgraduate School
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An experimental validation of the Schwartz-Hon computer code for emissivity of the rough sea surface in the grazing angle region was carried out using an AGEMA 780 thermovision radiometric sensor. The experimental measurements were made in Monterey Bay using a meteorological suite mounted on the Research Vessel Point Sur, with coordinated radiosonde launches. Predicted sea surface radiance was computer from reflected sky radiance and thermal sea emission, using the Schwartz-Hon algorithm for...
Topics: Systems engineering, Computer science, Thermal radiation, emissivity, blackbody radiators,...
This thesis examines how atmospheric conditions influence the performance of radar and Electronic Warfare systems. Of particular interest is the frequency of occurrence of various types of ducts in the Arabian Sea which is presented. Potential tactical advantage through better knowledge of ducting conditions is also examined. EREPS and IREPS, PC based programs for evaluating the atmospheric effects on radio systems, are addressed. An application of the above is the Airborne Microwave...
Topics: Electronics in military engineering, Electronic surveillance, Electronic intelligence, Command and...
Developing large hard-real-time systems in a traditional way usually creates inconsistencies among the user's needs, the requirements and the implementation. Rapid Prototyping by using Prototype System Description Language (PSDL) and Computer Aided Prototyping System (CAPS) minimizes the time and resource costs, and maximizes reliability. In this technique, designer builds the prototype with the initial requirements, and the user evaluates the actual behavior of the prototype against its...
Topics: ADA, C_x001B_p3_x001B_sI systems, Command and control systems., Computer aided prototyping,...